Hydrocarbons can be produced from wellbores of varying complexity that traverse one or more hydrocarbon-bearing subterranean formations. Multilateral wellbores, for example, include any number of lateral wellbores extending from a parent wellbore. In an example implementation, a casing exit (alternately referred to as a “window”) is provided in the parent wellbore at each lateral wellbore junction, and each casing exit allows the respective lateral wellbore to be drilled from the parent wellbore. The casing exit can be formed by positioning a whipstock in the parent wellbore and deflecting a mill laterally into the inner wall of casing or liner that lines the wellbore. The mill penetrates the casing to form the casing exit, following which a drill bit can be inserted through the casing exit to drill the lateral wellbore to a desired depth.
Some whipstocks are designed to allow a well operator to run the whipstock and one or more mills downhole together in a single run, which greatly reduces the time and expense of completing a multilateral wellbore. Such whipstock designs will typically anchor the mills to the whipstock using a shear bolt, which is designed to fail (shear) upon application of downward weight when a well operator desires to free the mills from the whipstock. The shear bolt is typically not designed to shear in torque, and if the shear bolt prematurely shears in torque as the whipstock is run downhole, the whipstock will have to be returned to the well surface and the shear bolt replaced.